Tesla has once again snapped its army of investors, social media followers and haters to attention, this time with a photographic reminder of the 70MW solar roof it is building on its Nevada Gigafactory, and a written reminder that this roof, once completed, will be largest of its kind anywhere in the world.

Gigafactory 1 will have the largest rooftop solar array in the world upon completion – 70MW or roughly ~200,000 solar panels pic.twitter.com/OMkfXg3r7a

The photo, seen in a Tesla tweet above, aims to show the progress of the array on the battery cell producing gigafactory – itself a work in progress – which was, reportedly, only recently resumed after kicking off in March.

As usual, the tweet attracted equal amounts of positive and negative feedback, with skeptics noting that aerial shots of the Gigafactory show little progress since March.

And the Gigafactory, itself, is also being built in stages, so that manufacturing can go on while works continue. Mass production of battery cells officially kicked off in January 2017.

Nevertheless, CEO and founder Elon Musk has tweeted that he expects the Gigafactory to be 100% renewable at the end of 2019.

And a recent tour of the facility by investment group Worm Capital seemed to impress that progress was ticking along nicely – although the solar roof did not rate a mention.

“Previous bottlenecks appear to have been remedied, and we’re increasingly optimistic in Tesla’s ability to hit— and sustain—weekly production rates of 6,000 Model 3 battery units per week, and with new Grohmann machine, scale to ~8,000 / week with minimal additional capital investment.”

According to Worm, those German-engineered Grohmann machines – pictured below – are expected to help make module production at the plant “three times faster, and three times cheaper.”